Having owned numerous WordPress blogs and forums in general I have noticed that I get better usage from forums. Unless you maintain an active blog and have quite a large audience who are willing to comment then you won't see much. What I mean by that is people will visit your site and no doubt read your blog posts, but nine times out of ten will not register to comment solely on that post. Forums are more engaging in my opinion and will keep members coming back to check on their posts and answers to their topics.
Hopefully that made sense. It made sense in my head as I was writing it. ?
Every WordPress instance I have had was intended for a website and not so much for a blog. Being someone that doesn't code and has no expertise in that department, I used it as a content management system (CMS) and it suited my needs. If I was to use another CMS I'd probably go for Ghost working in tandem with Flarum.